Gliese 876 e is an exoplanet orbiting the star Gliese 876 in the constellation of Aquarius. It is in a 1:2:4 Laplace resonance with the planets Gliese 876 c and Gliese 876 b: for each orbit of planet e, planet b completes two orbits and planet c completes four. This configuration is the second known example of a Laplace resonance after Jupiter's moons Io, Europa and Ganymede.[1] Its orbit takes 124 days to complete.
![]() An artist's impression of Gliese 876 e | |
Discovery | |
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Discovered by | Rivera et al. |
Discovery date | June 23, 2010 |
Detection method | Doppler spectroscopy |
Orbital characteristics | |
Epoch HJD 2,450,602.093 | |
Semi-major axis | 0.3343 ± 0.0013 [1] AU |
Eccentricity | 0.055 ± 0.012 [1] |
Orbital period (sidereal) | 124.26 ± 0.70 [1] d |
Mean anomaly | 335 ± 24 [1] |
Inclination | 59.5 [1] |
Argument of periastron | 239 ± 22 [1] |
Semi-amplitude | 3.42 ± 0.39 [1] |
Star | Gliese 876 |
Physical characteristics | |
Mass | 14.6 ± 1.7 [1] MEarth |
Gliese 876 e has a mass similar to that of the planet Uranus. Its orbit takes 124 days to complete, or roughly one third of a year. While the orbital period is longer than that of Mercury around the Sun, the lower mass of the host star relative to the Sun means the planet's orbit has a slightly smaller semimajor axis. Unlike Mercury, Gliese 876 e has a nearly circular orbit with an eccentricity of 0.055 ± 0.012.[1]
This planet, like b and c, has likely migrated inward.[2]
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Constellation of Aquarius | |||||||||||
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